How to save keras model in kedro

Question

I am able to save DNN Model in h5 format on s3. but when I import it in inference pipeline of kedro tool, I am getting blank?no predictions. I made following changes in catalog.yml file:

model:
  filepath: s3://ds-kedro/cuisine-classification-model/06_models/model.h5
  layer: models
  type: kedro.extras.datasets.tensorflow.TensorFlowModelDataset

I made changes in nodes.py as below:

    def train_model(multilabel_df: pd.DataFrame):
    """Use tokenizer to convert text to sequence and Use Deep Neural Network (DNN) to predict cuisines.
    Args: 
        feature_table: Contains restaurant names and cuisine code
    Returns:
        Model
    """
    tokenizer = Tokenizer(num_words=5000, lower=True)
    tokenizer.fit_on_texts(multilabel_df['detailed_name'])
    sequences = tokenizer.texts_to_sequences(multilabel_df['detailed_name'])
    x = pad_sequences(sequences, maxlen=200)
    X_train, X_test, y_train, y_test = train_test_split(x, 
                                                    
                         multilabel_df[multilabel_df.columns[1:]], 
                                                    test_size=0.1, 
                                                    random_state=42)
    num_classes = y_train.shape[1]
    max_words = len(tokenizer.word_index) + 1
    maxlen = 200
    model = Sequential()
    model.add(Embedding(max_words, 20, input_length=maxlen))
    model.add(GlobalMaxPool1D())
    model.add(Dense(num_classes, activation='sigmoid'))
    model.compile(loss='binary_crossentropy', metrics=['acc'])
    history = model.fit(X_train, y_train,
                    epochs=1,
                    batch_size=32,
                    validation_split=0.3,
                    )
    metrics = model.evaluate(X_test, y_test)
    print("{}: {}".format(model.metrics_names[1], metrics[1]))
    print('Predicting....')
    y_pred = model.predict(X_test,verbose=1)
    metric = HammingLoss(mode='multilabel', threshold=0.5)
    metric.update_state(y_test, y_pred)
    print("Hamming Loss is:",metric.result().numpy())
    #model.save('model.h5')  # creates a HDF5 file 'my_model.h5'
    #return model
    return dict(
        model=model,
        model_history=history.history,
    )

I have tried different methods like I put model in return statement and pass this parameter in inference pipeline.

def inference_pipeline(model, inference_data):
    pipeline code

It would be great help if somebody try to figure out whats wrong here becuase I am not getting error but also not getting any predictions(Blank values)

Answer 1

Hello @Rajesh this is where you should be saving your outputs via a pickle.PickleDataSet

The dataset supports several backends, it defaults to cpickle - but you can pass it additional backends like joblib or dill if helpful.

Answer 2

You can always save Keras models in Kedro using .hd5 format. You need to install the tensorflow.TensorFlowModelDataset dataset as an extra dataset support using

pip install kedro[<specify extra dataset>]

then

Add a specification in a catalog.yml file as:

your_model:
  type: tensorflow.TensorFlowModelDataset
  filepath: <path to save in local/s3>/your_model.hd5

You can use your_model in inference pipeline directly to predict.